The present invention relates to wheeled vehicles and in particular to trailered vehicles and the inclusion of means therewith for externally greasing the inner and outer wheel bearings of each wheel without removing the bearings.
One problem faced by the trailer owner is that of failed wheel bearings and axles and which arise from insufficient lubrication. This problem is of particular concern to the fisherman, in that with the insertion and removal of the trailer from the water, especially when the wheel bearings and grease are hot, the wheel grease tends to wash from the wheel hub and/or water is trapped in the hub with resulting rusting and accelerated wear. The rental trailer industry also shares in this problem, but there it is a consequence of protracted maintenance cycles. The resulting shortage of lubricant causing higher operating temperatures and resultant bearing failure. Some of the results in either case being worn bearings, pitted bearing races and/or possibly damaged wheel hubs, requiring the replacement thereof and/or oftentimes the replacement of the wheel's entire backing plate.
In order to alleviate the foregoing problems, a number of devices have been developed and which are disclosed in a number of U.S. Patents, for example, U.S. Pat. Nos. 3,077,948; 3,395,015; 3,649,080; 3,395,950; 3,955,852; 4,106,816; and 4,190,133. A feature common to each of the foregoing devices is that of including a zerk fitting in a special dust cap that mounts over the wheel hub and axle end. Grease injected into the grease fitting then permeates through the entire hub to grease the inner and outer bearings. In practice, however, with the buildup of old grease, this oftentimes does not occur and instead the new grease tends to build up in the region of the outer bearing, with no grease permeating to the inner bearing. Also and where water has leaked into the hub, as the old grease and water is forced out of the hub with the addition of new grease, it tends to ruin the inner grease seal. Thus, wheel failure tends to occur at the inner bearing and race.
Two attempts to overcome this problem can be seen in U.S. Pat. Nos. 3,460,874 and 3,642,237 and wherein zerk fittings have been mounted in the projecting external portion of the wheel hub itself and which ostensively permits the introduction of grease in between the bearings. Again, however, as the grease ages, one is not always certain that the newly injected grease will migrate to each of the wheel bearings, but may rather only collect in the middle region opposite the internal sides of the two bearings.
It is for the foregoing reasons that the present invention contemplates a modification of a conventional wheel hub and backing plate to permit the application of grease directly at each of the inner and outer bearings and thereby ensure proper bearing lubrication and the prolongation of the wheel's life. It achieves this end by providing grease ports that are accessible from the front of the wheel, but which channel the grease to the inner and outer bearings.
The above objects, advantages and distinctions, as well as the construction of the present invention, will however be described in greater detail hereinafter with respect to the appended drawings. Before referring thereto, it is to be recognized though that the following description is made with respect to the presently preferred embodiment only and is not intended to in any way be self-limiting.